RGD-CAP (βig-h3) Exerts a Negative Regulatory Function on Mineralization in the Human Periodontal Ligament

Abstract

In our previous studies, RGD-CAP/βig-h3 was isolated from a fiber-rich fraction of cartilage and was found to have a negative function on mineralization of hypertrophic chondrocytes. However, the expression and biological function of RGD-CAP in the periodontal ligament (PDL) are not known. We hypothesized that RGD-CAP could be expressed in the PDL and regulate its mineralization. To test this, we investigated the expression of RGD-CAP in human PDL and the effects of RGD-CAP on mineralization of cultured PDL cells. RGD-CAP was detected in the human PDL as multimeric proteins greater than 200 kDa. The RGD-CAP mRNA level decreased in cultured PDL cells exposed to 10⁻⁸ M dexamethasone or 10⁻⁸ M 1α,25-dihydroxyvitamin D₃ when these steroids increased alkaline phosphatase (ALP) activity. Furthermore, exogenous RGD-CAP suppressed the ALP activity and bone nodule formation of cultured PDL cells. These findings suggest that RGD-CAP in the PDL modulates the mineralization which affects adjacent alveolar bone metabolism.

Get full access to this article

View all access options for this article.

References

Chien HH, Lin WL, Cho MI -1999-. Expression of TGF-beta isoforms and their receptors during mineralized nodule formation by rat periodontal ligament cells in vitro. J Periodontal Res 34:301–309.

de Bernard B -1982-. Glycoproteins in the local mechanism of calcification. Clin Orthop 162:233–244.

Dieudonné SC, Kerr JM, Xu T, Sommer B, DeRubeis AR, Kuznetsov SA, et al. -1999-. Differential display of human marrow stromal cells reveals unique mRNA expression patterns in response to dexamethasone. J Cell Biochem 76:231–243.

Hashimoto K, Noshiro M, Ohno S, Kawamoto T, Satakeda H, Akagawa Y, et al. -1997-. Characterization of a cartilage-derived 66-kDa protein -RGD-CAP/beta ig-h3- that binds to collagen. Biochim Biophys Acta 1355:303–314.

Horiuchi K, Amizuka N, Takeshita S, Takamatsu H, Katsuura M, Ozawa H, et al. -1999-. Identification and characterization of a novel protein, periostin, with restricted expression to periosteum and periodontal ligament and increased expression by transforming growth factor beta. J Bone Miner Res 14:1239–1249.

Kawase T, Sato S, Miake K, Saito S -1988-. Alkaline phosphatase of human periodontal ligament fibroblast-like cells. Adv Dent Res 2:234–239.

Kim JE, Kim EH, Han EH, Park RW, Park IH, Jun SH, et al. -2000-. A TGF-beta-inducible cell adhesion molecule, beta ig-h3, is downregulated in melorheostosis and involved in osteogenesis. J Cell Biochem 77:169–178.

Leutenegger CM, von Rechenberg B, Huder JB, Zlinsky K, Mislin C, Akens MK, et al. -1999-. Quantitative real-time PCR for equine cytokine mRNA in nondecalcified bone tissue embedded in methyl methacrylate. Calcif Tissue Int 65:378–383.

Ohno S, Noshiro M, Makihira S, Kawamoto T, Shen M, Yan W, et al. -1999-. RGD-CAP --beta-ig-h3- enhances the spreading of chondrocytes and fibroblasts via integrin alpha-1-beta-1-. Biochim Biophys Acta 1451:196–205.

10.

Ohno S, Doi T, Tsutsumi S, Okada Y, Yoneno K, Kato Y, et al. -2002-. RGD-CAP -beta ig-h3- is expressed in precartilage condensation and in prehypertrophic chondrocytes during cartilage development. Biochim Biophys Acta 1572:114–122.

11.

Piche JE, Carnes DL Jr, Graves DT -1989-. Initial characterization of cells derived from human periodontia. J Dent Res 68:761–767.

12.

Ramakrishnan PR, Lin WL, Sodek J, Cho MI -1995-. Synthesis of noncollagenous extracellular matrix proteins during development of mineralized nodules by rat periodontal ligament cells in vitro. Calcif Tissue Int 57:52–59.

13.

Skonier J, Neubauer M, Madisen L, Bennett K, Plowman GD, Purchio AF -1992-. cDNA cloning and sequence analysis of beta ig-h3, a novel gene induced in a human adenocarcinoma cell line after treatment with transforming growth factor-beta. DNA Cell Biol 11:511–522.

14.

Somerman MJ, Foster RA, Imm GM, Sauk JJ, Archer SY -1989-. Periodontal ligament cells and gingival fibroblasts respond differently to attachment factors in vitro. J Periodontol 60:73–77.

15.

Sugiura T, Takamatsu H, Kudo A, Amann E -1995-. Expression and characterization of murine osteoblast-specific factor 2 -OSF-2- in a baculovirus expression system. Protein Expr Purif 6:305–311.

16.

Takeshita S, Kikuno R, Tezuka K, Amann E -1993-. Osteoblast-specific factor 2: cloning of a putative bone adhesion protein with homology with the insect protein fasciclin 1. Biochem J 294:271–278.

17.

Wang WC, Zinn K, Bjorkman PJ -1993-. Expression and structural studies of fasciclin 1, an insect cell adhesion molecule. J Biol Chem 268:1448–1455.